1. Field of the Invention
The present invention relates to an optical semiconductor device, a method for manufacturing an optical semiconductor device, and a method for manufacturing an optical module which can thereby easily measure the length of the window structure.
2. Background Art
In optical semiconductor devices with a window structure formed on a resonator end face, a length of the window structure varies depending on a position of cleavage for forming the resonator end face (e.g., see Japanese Patent Laid-Open No. 2000-216489).